Middleby Marshall IO_COMM_LOST: the CTX touch screen stopped hearing from its I/O board
A CTX oven splits its brain in two: the touch screen you press, and an input/output board that actually drives the infrared panels, fans and conveyor motors.
Mon–Sat, 8am–8pm
- Controls and power
- Commercial controls and board repair
- Source: Middleby Marshall
Book a visit
Three short steps, about a minute.
or call (844) 571-4566
Loading appointment form…
The appointment form couldn’t load. Please try again.
What IO_COMM_LOST
actually means.
A CTX oven splits its brain in two: the touch screen you press, and an input/output board that actually drives the infrared panels, fans and conveyor motors. If those two go 15 seconds without a message, the oven beeps and posts IO_COMM_LOST. The manual adds that this message takes priority over every other one, so any alarm that was active before it will show again once the link is restored.
Middleby Marshall commercial appliance display · also shown as IO_COMM_LOST
What to do when IO_COMM_LOST shows on the commercial applianceKind of codeControls and power
The controller itself is reporting trouble, or the supply behind it is: a display with dead segments, a keypad that stopped responding after steam or degreaser got behind it, relays that stick, stored recipes or cycles that vanished overnight, a blown control fuse, or one leg of a three-phase feed missing so half the heat or the pump is gone. A full power cycle at the breaker, done as the manual describes, clears a passing glitch; a code that returns, a scorched smell or any sign of moisture behind the panel means the breaker stays off, and that is a visit.
Usually leads toCommercial controls and board repair
Controllers, touch panels, relays, contactors and interlocks tested, and replaced only when the evidence says so.
Shows up asCommercial Appliance Error Code on a Combi, Fryer, Dish Machine or Laundry Display
A commercial appliance error code appears as letters or numbers on a combi, fryer, reach-in controller, dish machine or laundry machine display, or as a flashing light or an alarm tone.
MakeMiddleby Marshall
Middleby Marshall ovens on this site are the kitchen's non-pizza baking and roasting work; pizza service calls belong to our pizza oven site.
SourceMiddleby Marshall CTX DZ26T, DZ33T and DZ55T infrared conveyor oven owner's operating and installation manual (Rev G)
CTX DZ26T, DZ33T and DZ55T infrared conveyor ovens with the touch screen (manual Rev G). The message shows only on the Manual Mode and Preset Mode main screens.
Before you book,
in this order.
Each step comes from Middleby Marshall's own guidance for IO_COMM_LOST on its commercial appliances. Follow it to the end: the last card says whether this is a visit.
Touch the screen to acknowledge the message and watch whether the oven carries on normally.
Should it come back, switch the oven off, give it sixty seconds and turn it on again so both boards boot together.
Note any other message that shows up after the link returns, because the oven was hiding it while IO_COMM_LOST was active.
If IO_COMM_LOST keeps returning, book a visit; a loose harness, a failing I/O board or a power supply problem are technician checks.
Still there?
It usually turns into commercial controls and board repair. Book with the code and the model number.
What not to do
IO_COMM_LOST does not say the infrared panels have failed, only that the screen cannot confirm what they are doing. It is different from MC1_COMM_LOST and MC2_COMM_LOST, which concern the belt motor controls.
What you may
notice with it.
The commercial appliance problems IO_COMM_LOST tends to arrive with. Answer these at the commercial appliance before anyone is booked.
All problems
Where IO_COMM_LOST usually leads
Commercial controls and board repair.
Middleby Marshall
commercial appliances.
Middleby Marshall ovens on this site are the kitchen's non-pizza baking and roasting work; pizza service calls belong to our pizza oven site.
Middleby Marshall commercial appliance repairMore Middleby Marshall codes
Controls and power on other makes
In Middleby Marshall's own words
Communication between the User Interface and Input/Output (IO) has been interrupted for 15 seconds.
Every code on this site is taken from the manufacturer's documentation, never from a forum or a parts listing. CTX DZ26T, DZ33T and DZ55T infrared conveyor ovens with the touch screen (manual Rev G). The message shows only on the Manual Mode and Preset Mode main screens.
Middleby Marshall IO_COMM_LOST commercial appliance repair,
where we come out.
The same visit in every metro below: the code, the model number, and a diagnosis before any part is ordered.
All service areasTampa BayFL · 31 areas
Miami / South FloridaFL · 47 areas
New York MetroNY · 75 areas
HoustonTX · 36 areas
ChicagoIL · 50 areas
Los AngelesCA · 95 areas
San DiegoCA · 31 areas
Questions
about IO_COMM_LOST.
Can I clear IO_COMM_LOST myself?
Why did other alarms appear on my CTX oven right after IO_COMM_LOST cleared?
Can a CTX oven keep cooking during IO_COMM_LOST?
Does IO_COMM_LOST on a CTX mean the touch screen is broken?
Back to your everyday
Still showing IO_COMM_LOST?
A booking with a code goes further when it has the code as shown, the model and serial from the data plate, and a word on whether the unit still holds temperature, heats, rinses or spins. With those three, the office can match the likely part to your unit the same day.